Like in many other countries, German grooms traditionally wear a tuxedo or formal suit on the day of the wedding. Some people prefer wearing a bow tie over a tie ─ it’s up to the fashion sense of the groom! One flower of the bridal bouquet is traditionally positioned as a boutonnière onto the groom’s jacket.
If you're looking for a suit, the following links might help. Some couples find it important to match the colours of the groom's and bride's attire: you might want to ask the bride-to-be or her maid of honour for advice (Note: some of the following websites are in German).
In a multicultural city like Hamburg, there is no need to celebrate your wedding following German traditions. Whether you're looking for a Turkish, Greek, Polish, Pakistani, Hindi or another kind of celebration, several shops in Hamburg are likely to specialise in what you need. The Steindamm near Hauptbahnhof is known for the cultural diversity of its shops.